The present invention relates generally to implantable ophthalmic devices to assist in vision correction. Standard tools for correction of various vision defects such as presbyopia include reading glasses, multifocal ophthalmic lenses, and contact lenses fit to provide monovision. Some vision correction techniques involve implanting a form of lens into the eye itself. For example, Pseudophakia is the replacement of the crystalline lens of the eye with an intra-ocular lense (IOL), usually following surgical removal of the crystalline lens during cataract surgery. In a pseudophakic individual, the absence of the crystalline lens causes a complete loss of accommodation that results in an inability to focus on either near or intermediate distance objects.
Conventional IOLs are monofocal, spherical lenses that provide focused retinal images for far objects (e.g., objects over two meters away). Generally, the focal length (or optical power) of a spherical IOL is chosen based on viewing a far object that subtends a small angle (e.g., about seven degrees) at the fovea. Unfortunately, because monofocal IOLs have a fixed focal length, they are not capable of mimicking or replacing the eye's natural accommodation response. Ophthalmic devices with electro-active elements, such as liquid crystal cells, can be used to provide variable optical power as a substitute for the accommodation of an damaged or removed crystalline lens. For example, electro-active elements can be used as shutters that provide dynamically variable optical power as disclosed in U.S. Pat. No. 7,926,940 to Blum et al., which is incorporated herein by reference in its entirety. IOLs with electro-active elements and other electronic components must be well sealed to prevent potentially foreign substances, such as the liquid crystal materials used in the electro-active elements, from leaking into the eye and surrounding tissue.
Furthermore, cavities of the IOL that contain electrical components must be properly sealed such that no bodily fluid from the ocular region will be able to interfere with the functionality of the electrical components. Additionally, the system and methods of sealing electrical components of the IOL must be durable over a long period of time. To date, IOLs with electro-active elements and other electronic components have been made by potting or encapsulating the components in a shell of epoxy, polyurethane, or another suitable type of curable compound. However, potting compounds do not always adhere well to the biocompatible metals used for electrical connections in IOLs. Potting compounds may also degrade over an IOL's expected lifetime, which can be twenty years or more.